A survey of herbaceous plants and grasses of the Berry College Longleaf Management Area

Background/Question/Methods

The Berry College (Mount Berry, Georgia) Longleaf Pine Management Area consists of old growth fire-suppressed mountain longleaf pine (Pinus palustris) stands embedded within an encroaching matrix of mixed hardwood forest.  This forest had likely been fire suppressed for decades prior to the initiation of long-term study in 1999.  Since 2001, portions of the management area have been subjected to restoration efforts involving clear- and selective-logging followed by burning, herbicide application and planting, and prescribed burning and hardwood control using herbicides in old growth stands.  An important question is the impact of these management practices on understory plants and grasses.  In fact, relatively little is known at all about native groundcover species in mountain longleaf pine forests.  To begin to address these issues, from May 2008 to May 2009, flowering plant specimens were identified in the understory of stands ranging from relatively unmanaged old growth areas to intensively managed selective- and clear-cuts.  The principal goal was to establish species inventories for areas differing in recent management history.

Results/Conclusions

Two hundred twenty species were identified in about 30 different families across all management areas.  Although grass diversity was obviously higher in selective- and clear-cut areas, many grass species and all sedge and rush species were also collected in managed old growth stands.  These results suggest that management activities that have reduced tree canopy density have already resulted in some recovery of herbaceous and grass species diversity, particularly among light-tolerant species, since understory plant diversity in the least intensively managed old growth stands was extremely low.  We compared our species list with a species list from mountain slopes at Berry College in the 1940s and with lists of characteristic species present at several other mountain longleaf pine sites in Georgia and Alabama.  These comparisons reveal species that may have invaded more intensively managed areas as well as species that may have gone locally extinct in old growth stands during the extended period of fire suppression.  The former species are mostly weedy or broadly-distributed species that tend to respond quickly to disturbance.  The latter set of species are likely to be species that have disappeared during the period of fire suppression due to lack of shade tolerance, short life span, and/or little or no long-term seed dormancy.  This set of species may be the target of future efforts to restore native groundcover species of mountain longleaf pine habitats.